Research On Dry Cutting Performance Of Surface Micro-texture Carbide Tool

The application of dry cutting is more and more extensive due to the harm of cutting fluid to the environment and operators,but tool life and machining quality are reduced because of violently friction and adhesion caused by drying cutting.Since the non-smooth frictional surface(surface texture)with microstructure has a smaller frictional force,the friction and wear of the cutting tools are reduced due to the application of surface texture,but the mechanism of texture on the dry cutting process is still unclear.In order to improve the cutting performance of tools,this paper aims to explore the mechanism of micro-texture on dry cutting process combining mechanics,material science and modern cutting theory,the design,preparation and cutting performance of micro-texture tools are studied combining with finite element analysis and cutting experiments.The main research contents are as follows.(1)The finite element analysis of the cutting process of non-free and oblique cutting of 45 steel is carried out.The cutting force,cutting temperature and stress of MT-0,MT-45,MT-90 and MT-135 tools are contrastive analyzed.The results show that the cutting temperature and stress distribution of tools are changed by micro-texture.The effect of different width,depth and pitch of micro-texture on the cutting temperature and stress are studied.The changes of cutting temperature and stress with cutting speed,feed rate and backwash knife are investigated.The "secondary cutting" phenomenon caused by micro-texture is studied,and the result shows that the smaller width-depth ratio of micro-texture can avoid this phenomenon.(2)MT-0,MT-45,MT-90 and MT-135 tools are fabricated by laser processing technology.The morphology of micro-texture is measured after post processing.The effect of micro-texture morphology on the three-direction cutting force,the average friction coefficient of the rake face and the bonding morphology of the rake face are analyzed by dry cutting experiment.The changes of cutting force and the average friction coefficient of the rake face of non-textured tool and MT-135 tool along with width and depth of micro-texture,cutting speed,feed rate and backwash knife are studied.(3)The effect of micro-texture shape on chip morphology is studied.Through the analysis of the formation process and the crimping method,the chip formation mechanism of the micro-texture tool is discussed.The mechanism of the surface micro-texture on dry cutting process is revealed.The actual contact length of the tool-chip is reduced because of micro-texture in cutting process,and it is beneficial to reduce the cutting force and cutting temperature.The debris from frictional interface of the tool-chip can be stored by micro-texture,and the friction and wear are reduced by reducing the plowing effect.